[MLB-WIRELESS] ./: Can 802.11 Become A Viable Last-Mile Alte rnative?

[dwayne]

Tony Langdon wrote:

> UWB has been given a bit of bad press, but from my understanding of how it
> works, it's an extreme form of spread spectrum, and as a result, could be
> very resistant to interference, and at the same time, not likely to cause
> problems, except for very nearby systems.

Well, not really, spread spectrum involves rapidly hopping from one
frequency to another, with so little time in each frequency that there
is little overall interference.  UWB involves transmissions across the
entire RF band of picosecond duration, but with very little power being
transmitted.  I think.

> The reason for the bad press is that to the unitiated, UWB sounds rather
> "dirty", spreading energy over a wide range of frequencies, but if that's
> done properly, it can work rather well with minimal interference (the whole
> idea of spread spectrum - make the signal immune to jamming, and as
> difficult to detect as possible - and as you might guess, spread spectrum
> was first developed by the military).

Errr, sure, but you seem to have the wrong idea of SS. It's all about
frequency hopping, this is all about spreading the signal across the
frequency domain while concentrating it in the time domain.

I may have this wrong, but that's how I read it. 

Dwayne

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